<?php

/**
 * JPGraph v4.0.3
 */

namespace lemon\JpGraph\Image;

use lemon\JpGraph\Util;

/**
 * File:		JPGRAPH_IMGTRANS.PHP
 * // Description: Extension for JpGraph to do some simple img transformations
 * // Created:	 2003-09-06
 * // Ver:		 $Id: jpgraph_imgtrans.php 1106 2009-02-22 20:16:35Z ljp $
 * //
 * // Copyright (c) Asial Corporation. All rights reserved.
 */

/**
 * @class ImgTrans
 * // Perform some simple image transformations.
 */
class ImgTrans
{
	private $gdImg;

	public function __construct($aGdImg){
		// Constructor
		$this->gdImg = $aGdImg;
	}

	// --------------------------------------------------------------------
	// _TransVert3D() and _TransHor3D() are helper methods to
	// Skew3D().
	// --------------------------------------------------------------------
	public function _TransVert3D($aGdImg, $aHorizon = 100, $aSkewDist = 120, $aDir = SKEW3D_DOWN, $aMinSize = true, $aFillColor = '#FFFFFF', $aQuality = false, $aBorder = false, $aHorizonPos = 0.5){
		// Parameter check
		if ($aHorizonPos < 0 || $aHorizonPos > 1.0) {
			Util\JpGraphError::RaiseL(9001);
			//("Value for image transformation out of bounds.\nVanishing point on horizon must be specified as a value between 0 and 1.");
		}

		$w = imagesx($aGdImg);
		$h = imagesy($aGdImg);

		// Create new image
		$ww = $w;
		if ($aMinSize) {
			$hh = ceil($h * $aHorizon / ($aSkewDist + $h));
		} else {
			$hh = $h;
		}

		$newgdh	= imagecreatetruecolor($ww, $hh);
		$crgb	  = new RGB($newgdh);
		$fillColor = $crgb->Allocate($aFillColor);
		imagefilledrectangle($newgdh, 0, 0, $ww - 1, $hh - 1, $fillColor);

		if ($aBorder) {
			$colidx = $crgb->Allocate($aBorder);
			imagerectangle($newgdh, 0, 0, $ww - 1, $hh - 1, $colidx);
		}

		$mid = round($w * $aHorizonPos);

		$last = $h;
		for ($y = 0; $y < $h; ++$y) {
			$yp = $h - $y - 1;
			$yt = floor($yp * $aHorizon / ($aSkewDist + $yp));

			if (!$aQuality) {
				if ($last <= $yt) {
					continue;
				}

				$last = $yt;
			}

			for ($x = 0; $x < $w; ++$x) {
				$xt = ($x - $mid) * $aSkewDist / ($aSkewDist + $yp);
				if ($aDir == SKEW3D_UP) {
					$rgb = imagecolorat($aGdImg, $x, $h - $y - 1);
				} else {
					$rgb = imagecolorat($aGdImg, $x, $y);
				}

				$r	  = ($rgb >> 16) & 0xFF;
				$g	  = ($rgb >> 8) & 0xFF;
				$b	  = $rgb & 0xFF;
				$colidx = imagecolorallocate($newgdh, $r, $g, $b);
				$xt	 = round($xt + $mid);
				if ($aDir == SKEW3D_UP) {
					$syt = $yt;
				} else {
					$syt = $hh - $yt - 1;
				}

				if (!empty($set[$yt])) {
					$nrgb   = imagecolorat($newgdh, $xt, $syt);
					$nr	 = ($nrgb >> 16) & 0xFF;
					$ng	 = ($nrgb >> 8) & 0xFF;
					$nb	 = $nrgb & 0xFF;
					$colidx = imagecolorallocate(
						$newgdh,
						floor(($r + $nr) / 2),
						floor(($g + $ng) / 2),
						floor(($b + $nb) / 2)
					);
				}

				imagesetpixel($newgdh, $xt, $syt, $colidx);
			}

			$set[$yt] = true;
		}

		return $newgdh;
	}

	// --------------------------------------------------------------------
	// _TransVert3D() and _TransHor3D() are helper methods to
	// Skew3D().
	// --------------------------------------------------------------------
	public function _TransHor3D($aGdImg, $aHorizon = 100, $aSkewDist = 120, $aDir = SKEW3D_LEFT, $aMinSize = true, $aFillColor = '#FFFFFF', $aQuality = false, $aBorder = false, $aHorizonPos = 0.5){
		$w = imagesx($aGdImg);
		$h = imagesy($aGdImg);

		// Create new image
		$hh = $h;
		if ($aMinSize) {
			$ww = ceil($w * $aHorizon / ($aSkewDist + $w));
		} else {
			$ww = $w;
		}

		$newgdh	= imagecreatetruecolor($ww, $hh);
		$crgb	  = new RGB($newgdh);
		$fillColor = $crgb->Allocate($aFillColor);
		imagefilledrectangle($newgdh, 0, 0, $ww - 1, $hh - 1, $fillColor);

		if ($aBorder) {
			$colidx = $crgb->Allocate($aBorder);
			imagerectangle($newgdh, 0, 0, $ww - 1, $hh - 1, $colidx);
		}

		$mid = round($h * $aHorizonPos);

		$last = -1;
		for ($x = 0; $x < $w - 1; ++$x) {
			$xt = floor($x * $aHorizon / ($aSkewDist + $x));
			if (!$aQuality) {
				if ($last >= $xt) {
					continue;
				}

				$last = $xt;
			}

			for ($y = 0; $y < $h; ++$y) {
				$yp = $h - $y - 1;
				$yt = ($yp - $mid) * $aSkewDist / ($aSkewDist + $x);

				if ($aDir == SKEW3D_RIGHT) {
					$rgb = imagecolorat($aGdImg, $w - $x - 1, $y);
				} else {
					$rgb = imagecolorat($aGdImg, $x, $y);
				}

				$r	  = ($rgb >> 16) & 0xFF;
				$g	  = ($rgb >> 8) & 0xFF;
				$b	  = $rgb & 0xFF;
				$colidx = imagecolorallocate($newgdh, $r, $g, $b);
				$yt	 = floor($hh - $yt - $mid - 1);
				if ($aDir == SKEW3D_RIGHT) {
					$sxt = $ww - $xt - 1;
				} else {
					$sxt = $xt;
				}

				if (!empty($set[$xt])) {
					$nrgb   = imagecolorat($newgdh, $sxt, $yt);
					$nr	 = ($nrgb >> 16) & 0xFF;
					$ng	 = ($nrgb >> 8) & 0xFF;
					$nb	 = $nrgb & 0xFF;
					$colidx = imagecolorallocate(
						$newgdh,
						floor(($r + $nr) / 2),
						floor(($g + $ng) / 2),
						floor(($b + $nb) / 2)
					);
				}
				imagesetpixel($newgdh, $sxt, $yt, $colidx);
			}

			$set[$xt] = true;
		}

		return $newgdh;
	}

	// --------------------------------------------------------------------
	// Skew image for the apperance of a 3D effect
	// This transforms an image into a 3D-skewed version
	// of the image. The transformation is specified by giving the height
	// of the artificial horizon and specifying a "skew" factor which
	// is the distance on the horizon line between the point of
	// convergence and perspective line.
	//
	// The function returns the GD handle of the transformed image
	// leaving the original image untouched.
	//
	// Parameters:
	// * $aGdImg, GD handle to the image to be transformed
	// * $aHorizon, Distance to the horizon
	// * $aSkewDist, Distance from the horizon point of convergence
	//   on the horizon line to the perspective points. A larger
	//   value will fore-shorten the image more
	// * $aDir, parameter specifies type of convergence. This of this
	//   as the walls in a room you are looking at. This specifies if the
	//   image should be applied on the left,right,top or bottom walls.
	// * $aMinSize, true=make the new image just as big as needed,
	//   false = keep the image the same size as the original image
	// * $aFillColor, Background fill color in the image
	// * $aHiQuality, true=performa some interpolation that improves
	//   the image quality but at the expense of performace. Enabling
	//   high quality will have a dramatic effect on the time it takes
	//   to transform an image.
	// * $aBorder, if set to anything besides false this will draw a
	//   a border of the speciied color around the image
	// --------------------------------------------------------------------
	public function Skew3D($aHorizon = 120, $aSkewDist = 150, $aDir = SKEW3D_DOWN, $aHiQuality = false, $aMinSize = true, $aFillColor = '#FFFFFF', $aBorder = false){
		return $this->_Skew3D(
			$this->gdImg,
			$aHorizon,
			$aSkewDist,
			$aDir,
			$aHiQuality,
			$aMinSize,
			$aFillColor,
			$aBorder
		);
	}

	public function _Skew3D($aGdImg, $aHorizon = 120, $aSkewDist = 150, $aDir = SKEW3D_DOWN, $aHiQuality = false, $aMinSize = true, $aFillColor = '#FFFFFF', $aBorder = false){
		if ($aDir == SKEW3D_DOWN || $aDir == SKEW3D_UP) {
			return $this->_TransVert3D($aGdImg, $aHorizon, $aSkewDist, $aDir, $aMinSize, $aFillColor, $aHiQuality, $aBorder);
		}

		return $this->_TransHor3D($aGdImg, $aHorizon, $aSkewDist, $aDir, $aMinSize, $aFillColor, $aHiQuality, $aBorder);
	}
}
